I think it was a decision by the producers to spice it up. They could obviously see that the six were unlikely to split and the next few tribals/episodes would be fairly boring.
This 3/3 exile thing essentially forces the six to divide next episode, and hence make it easier for them to create storylines and more compelling TV for the viewers.
This is true - although if they’d only had 4 return out of the 6 that could have been more effective (and arguably would have made sense, given it’s two tribals worth of voting to get them all there ... maybe they are also slowing things down, given Lee’s unexpected departure).
AK is pretty decent at puzzles from memory, and he can throw well - so he’s a chance to come first on one of those and save himself, if that’s the structure (which I assume it will be - ie volatility is good, not bad).
Moana is pretty consistently poor form what I recall, except maybe for things like the basketball one today where a combo of decent strength and some skill might be required (that one being one on one vs another female participant, which I suspect won’t be the structure on exile - my guess is it will be 6 individuals competing all against each other, then 5 on a different challenge, and so on).
I quite like the memory ones and those that test how much people have bothered to get to know their fellow tribe mates. Someone like Shonee would be great at that, although it depends on how much time she’s had with the people she’s up against.